<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      class A {
        constructor(name) {
          this.name = name;
        }
        eat() {
          console.log(111);
        }
      }
      class C {
        constructor(age) {
          this.age = age;
        }
        eat() {
          console.log(111);
        }
      }
      class B {
        constructor() {}
      }
      let obj = {
        A: function () {
          return new A();
        },
        _B() {
          return new B();
        },
      };
      let a = obj["A"]();
      console.log(a);
    </script>
  </body>
</html>
